1. Field of the Invention
The present invention pertains to load-carrying, movable structures, and more particularly it pertains to apparatus for stacking or ricking cotton or the like.
2. Description of the Prior Art
Until rather recently, cotton was usually picked by a mechanical harvester, loaded in wagons, and transported to the gin for subsequent processing. This resulted in a glut of activity at the gin during or shortly after harvesting time and a dearth of gin activity during the remainder of the year. The cotton module builder, as disclosed in U.S. Pat. No. 3,749,003 to Wilkes et al., was developed in part to allow the formation of large modules of cotton (sometimes twenty thousand pounds or more) in the cotton fields, which modules are of uniformly high density and may be temporarily stored where they lie until it is convenient to transport them to the gin. This allows inter alia a spacing out of the gin activities, with a consequent savings in cost resulting from the extension of the ginning season.
The cotton module builder generally comprises a rectangular frame structure which is open at the top and bottom and which is provided with collapsible wheels so that it can be transported to and from the fields where the cotton is harvested. At a suitable location the frame structure is lowered relative to the wheels so that it can be brought into engagement with the ground in closely spaced surrounding relationship to a flat pallet which rests upon the ground surface. The cotton which is harvested is dumped into the open body of the module builder upon the underlying pallet. A carriage containing a vertically reciprocable tamper is mounted upon the top of the frame structure so that the cotton can be continuously compressed into a firm, self-supporting stack or module, within the confines of the frame structure. When the cotton module is completed, the rear gate of the apparatus is opened and the wheels are extended to allow the module builder to be pulled forwardly to a new location leaving the compressed cotton on the pallet for temporary field storage.
In the module builder as conventionally constructed, the rear gate of the machine is a critical element in maintaining the structural integrity of the machine. When the tail gate pins (normally in shear, when the module builder is loaded with cotton) are removed and the rear gate is opened, the machine becomes essentially a three-sided open structure as it has no elements connecting the side frame members on the bottom thereof (in contact with the ground). One result of this is low torsional resistance in the module builder structure when the rear gate is opened, which circumstance is aggravated by the presence of a full load of tamped cotton within the builder. This also gives rise to substantial horizontal deflections at the base of the machine with the load of tamped cotton in place. The high torsional forces generated by the compressed cotton occasionally result in buckling or cracking of the structure at the corners thereof. Further, the opening and closing of the rear door with a tamped cotton load in place is often difficult as the rear door tends to "bind" due to various bending stresses. Finally, even with the rear door closed, changes in lateral wheelbase (center-to-center distance of parallel tires on the machine) can occur, thus presenting a safety hazard at even a 20 mile per hour towing speed.
One further problem, related to the transport of the module builder, occurs when the unit is moved over uneven or undulatory ground. The main frame, if attached rigidly to the wheel structure, will tend to rock back and forth and to "bottom" or bump along the ground as it moves, due to the uneven terrain.